I have a central a/c unit outside of the house. When I turn it on it blows cold air through the vents, but after ten minutes (sometimes more, sometimes less depending on outdoor temperature) the condenser fan motor shuts down. Once that motor quits then warm air blows through the vents. I checked the condenser fan motor and found that the motor spins freely with no bearing noise. Does anyone have a recommendation as to what I might look into here?

mygirlsdad77

Jul 21, 2009, 03:55 PM

Does the compresser keep running? If it does, and only the fan motor stops running, I would first check to see if your condenser coil is completely clogged, cuasing fan motor to overheat and go out on internal overload. If conderser coil is clean, then you will need a new fan motor, as it is just worn out. Good luck and please let me know what you find.

SoCal2hot 4now

Jul 22, 2009, 12:19 AM

Mygirlsdad77,

Thank you for the recommendation! The cleaning will be taken care of tomorrow, the22nd.
The unit has not been cleaned since I've lived here, so that's six years. As for the compressor, it continues to run after the fan has quit. We'll see what happens tomorrow and I will let you know what the result is. Thanks again!

SoCal2hot 4now

Jul 22, 2009, 10:18 PM

Mygirlsdad77,
The test run of the a/c following the cleaning of the condenser coils yielded the same result. It appears that I will now chase after a new condenser fan motor and the other necessary related components required. If you have any other thoughts that you think might be useful please send them. I'm happy to receive whatever ideas you may have!

mygirlsdad77

Jul 23, 2009, 03:54 PM

Best to replace fan motor capacitor when replacing fan motor.

Also, if your motor has oil ports, try oiling them, a few drops will do. This may cure the problem(iffy, but worth a try).

T-Top

Jul 23, 2009, 07:37 PM

A bad run capacitor ($5.00) will cause the motor to over heat and shut off.

SoCal2hot 4now

Jul 24, 2009, 10:15 PM

Dear Mygirsldad77 and T-Top,

I've taken the plunge and have purchased a replacement motor and run capacitor. It's taking me some time to get it installed as other domestic demands arise. I'm in the middle of the reinstallation at present. The items are from Grainger and are very reasonably priced!
Since the motor is a "universal" type there are some additional steps to go through with the installation, but nothing unusual. I will let you know what happens after the test run tomorrow! Thank you for your comments and interest!

SoCal2hot 4now

Jul 25, 2009, 04:55 PM

Mygirlsdad77 and T-Top,

I completed the condenser fan motor installation without any modification. The fan is now about an inch lower inside the unit so it's closer to the condenser manifold, but there's still an inch or more between them. The shorter distance makes me a little nervous, but it's running just fine! Could there be a benefit to having the fan somewhat closer to the compressor as it may draw the hot air out a little more quickly?

I had a problem with the replacement capacitor and so I'm using the old one for now. There are no external tell-tale signs that it's going bad. Physically it appears okay.
1) There were three contact locations on the original and only two on the replacement. There is a contact specifically marked for the fan on the old cap which the new one lacked. This appears to be critically important.
2) The new unit has four wires (black, purple, brown, and brown/white) and I'm not using the brown/white. I learned this from another forum.
3) Wiring instructions placed on the new motor were not fully accurate. The purple and black wires were supposed to placed at the contacts beside each of the incoming power wires at L1 (pur) and L2 (blk) on the contactor. This caused the motor to run non-stop. I relocated those wires to T1 (pur) and T2 (blk). The brown wire went to the single contact location of the cap marked for the fan. Once that was done-and this was after much consternation over trying to use the new capacitor and having the two 30 amp fuses blow-the motor and compressor fired up and have been on for nearly an hour.

This has been a great learning experience and I appreciate your joining in on this with me. If you have any last thougts please send them along, I'd be delighted to read them! Thanks again!

siberianair

Jul 25, 2009, 06:21 PM

Usually the dan needs to be further. The blade is to be in a certain spot to make it work.
I figured something would come up being you went to grainger. Always happens when people go to them.

SoCal2hot 4now

Jul 26, 2009, 01:53 PM

usually the dan needs to be further. the blade is to be in a certian spot to make it work.
i figured something would come up being you went to grainger. always happens when people goto them.

Siberianair,

What is the "dan" in your first sentence referring to? If the fan needs to be located lower on the shaft so that it's nearer to the vents the modification is fairly simple, merely cutting down the mounting studs on the other side (interior) of the motor. Thank you for your comments!

wmproop

Jul 26, 2009, 02:31 PM

I think the "dan" was a typo for "fan"
Lol,the d and f are right beside each other

SoCal2hot 4now

Jul 26, 2009, 11:06 PM

I think the "dan" was a typo for "fan"
lol,the d and f are right beside each other

That sounds reasonable, wmproop. God knows I've made my share of typos and there are probably more to come somewhere down the line from here!

SoCal2hot 4now

Jul 28, 2009, 04:28 PM

All is complete and the condenser fan functions perfectly. However, arriving at perfection was a bit slow.

In order to get the correct capacitor, a dual capacitor, Grainger needed to supply a different motor. In this case it was an improvement since the original motor and it's first replacement were rated at 1/6 horse power. The second motor is a 1/4 horsepower motor with the same rpm rating. So the motor doesn't work quite so hard.

The new motor was less expensive, but the dual capacitor cost more. My final cost was more the it started to be, but only by about eight dollars. Although there were some difficulties going through this installation it was instructive to me, a non-hvac repairman, and that was valuable.

Thank you to all who followed this with me and provided very useful assistance! The kindness of sharing your time with me has been greatly appreciated!

mygirlsdad77

Jul 29, 2009, 04:48 PM

Thanks for the update, we always appreciate that. Good job, take care. Lee